The ancient mariner and explorer known for mapping the Pacific Islands was Captain James Cook. A British explorer, navigator, and cartographer, Cook undertook three major voyages to the Pacific Ocean in the 18th century. His expeditions significantly expanded European knowledge of this vast region and included detailed maps of the coasts of New Zealand, Australia, and various Pacific islands. Cook's encounters with different cultures and environments significantly contributed to the European understanding of the Pacific and influenced subsequent exploration and colonization efforts. His voyages are considered among the most important in the history of exploration.